On The Block: Two Generations of Patek Philippe Perpetual Calendar Chronographs At Bonhams New York (Live Pics)

Many would consider the perpetual calendar chronograph the quintessential Patek Philippe. And for their December 13th sale, Bonhams has two generations of this amazing watch, a first generation 2499 and the later 3970. We went hands-on with these two pieces for a detailed side-by-side comparison.

Many would consider the perpetual calendar chronograph the quintessential Patek Philippe. And in their December 13th sale, Bonhams New York has two generations of this amazing watch, a first generation 2499 and the later 3970. We went hands-on with these two pieces for a detailed side-by-side comparison.

First Series 2499

Let's start with the 2499. As we have explained before, there are four unique generations of 2499s out there. This is an example from circa 1955 that comes from the first series, making it highly desirable, and the estimate is $250,000-300,000. Across all four series, only 349 2499s left Patek Philippe's manufacture over the course of 35 years. And there are a number of features that distinguish the first series from subsequent 2499s.

A Closer Look At The 2499

First off are the rectangular chronograph buttons, which became round with the move to the second series. Other features, like the tachymeter scale, were shared between the first and second series, while others, like the Arabic numerals, were available but not requisite on second series 2499s (batons were introduced and became the only choice for series three and four). By the time we get to the fourth generation you are looking at a watch that aesthetically bears few similarities to the original - round buttons, applied baton numerals, outer seconds division, and a sapphire crystal are all departures from the first series configuration.

Second Generation 3970

After the fourth series of 2499, Patek Philippe replaced the 2499 with the 3970, which itself was produced in three generations. The example here is a second generation from 1988, and next to the first series 2499 you can get a really good sense of the direction Patek Philippe was pushing its perpetual calendar chronograph over time. Instead of arabic numerals we have straight baton hour markers, screw back case in place of snap back, and, most significantly, a reduced 35mm size.

Closer Look At The 3970

You'll also notice the many cosmetic and functional differences apparent on the dial. The seconds register has had a 24 hour indicated added to to interior and opposite the chronograph minutes register has the leap year indicated inside. The hands are slimmer and although there is more information being displayed in less space the dial has a distinctly cleaner appearance. This example happens to have the date written in Italian (which certainly amps up the cool factor) and the estimate is $80,000-$100,000